Lot Calculator
A lot calculator for land, not for trading: this one measures a parcel. Pick the shape that matches your lot (rectangle, square, circle or triangle), enter the dimensions in feet, meters or yards, and it returns the area in the unit you used plus square feet, square meters and acres, the perimeter in feet, and an estimated value when you add a price per square foot.
Optional. The value estimate is area in square feet times this price.
Total Area
Quick Answer
A rectangular lot 100 ft long by 80 ft wide covers 8,000.00 sq ft, which is 743.22 sq m and 0.1837 acres, with a 360.00 ft perimeter. At the pre-filled price of $25 per square foot the tool puts its estimated value at $200,000.00. The calculator above is pre-filled with this exact lot.
Key takeaways
- This page’s “lot” is a parcel of land. It is not a forex or stock trading lot, not a parking lot, and not an inventory order quantity.
- One unit governs the whole shape. The width and height fields have no unit of their own, so both dimensions must be measured in the unit picked beside the first dimension.
- One acre is 43,560 sq ft. Divide any area in square feet by 43,560 to get acres, which is exactly what the tool does.
- The triangle perimeter assumes the two slanted sides are equal. The triangle area (half base times height) holds for any triangle whose height is the perpendicular altitude.
- Quick Answer
- How to use the lot calculator
- The formulas behind each shape
- Worked example: a 100 by 80 ft lot at $25 per square foot
- Common lot sizes in acres
- Which “lot” do you actually mean?
- Irregular lots: split, calculate, add
- What competing calculators miss
- Frequently asked questions
- Add This Calculator to Your Website
How to use the lot calculator
Choose the shape, enter its dimensions in one unit, and add a price per square foot only if you want the value estimate. Results stay hidden until you click Calculate.
- Shape: Rectangle covers most house lots. Square needs one side. Circle needs the radius, half the distance across. Triangle needs a base and the perpendicular height from that base to the far corner.
- Dimensions and unit: the unit select sits beside the first dimension (length, side, radius or base) and applies to every dimension of the shape. A 100 by 80 lot in feet and a 100 by 80 lot in meters are very different parcels, so check the unit before the numbers.
- Price per square foot (optional): take it from the listing or a nearby sale. The estimate is the area in square feet times this price, so a price quoted per acre must be divided by 43,560 first.
- Read the result: the headline is the area in the unit you entered, followed by square feet, square meters, acres and the perimeter in feet. The perimeter is the number you need for fencing runs; if you are pricing that fence, the fence price calculator turns a perimeter into a materials and cost estimate.
If acres are the only number you need and the parcel is a simple rectangle, the dedicated acreage calculator goes deeper on acreage conversions and irregular parcels. This page is the broader shape tool: four shapes, three units, a perimeter and a price estimate in one run.
The formulas behind each shape
Each shape uses its standard geometry formula, then the result is converted with fixed factors: square meters and yards are converted at 10.764 sq ft per sq m and 9 sq ft per sq yd, perimeters at 3.281 ft per meter and 3 ft per yard, and acres at 43,560 sq ft per acre. Those factors follow the conversion tables in the National Institute of Standards and Technology’s Guide to the SI (SP 811), rounded the way the tool rounds them.
Square: Area = Side × Side; Perimeter = 4 × Side
Circle: Area = π × Radius²; Perimeter (circumference) = 2 × π × Radius
Triangle: Area = (Base × Height) ÷ 2; Perimeter = Base + 2 × √((Base ÷ 2)² + Height²)
Acres: Area in square feet ÷ 43,560 | Estimated value: Area in square feet × Price per square foot
Read the triangle perimeter formula carefully. It builds the two slanted sides from the base and height as if the apex sat over the middle of the base, so it is exact for an isosceles triangle and an approximation for a lopsided one. The area needs no such assumption: half the base times the perpendicular height is correct for every triangle. Land area itself is a surveyed quantity in legal records; the Bureau of Land Management’s Manual of Surveying Instructions is the reference US surveyors work from, and the deed or plat figure is the one that counts in a dispute.
Worked example: a 100 by 80 ft lot at $25 per square foot
The pre-filled run is a rectangular lot, 100 ft by 80 ft, priced at $25 per square foot. The table below adds the other three shapes at the pre-filled sizes so you can see every output line the tool produces, and every row was run through the calculator itself.
| Run | Total area | Square feet | Acres | Perimeter |
|---|---|---|---|---|
| Rectangle 100 × 80 ft, $25/sq ft | 8,000.00 sq ft | 8,000.00 | 0.1837 | 360.00 ft |
| Square, 100 ft side | 10,000.00 sq ft | 10,000.00 | 0.2296 | 400.00 ft |
| Circle, 50 ft radius | 7,853.98 sq ft | 7,853.98 | 0.1803 | 314.16 ft |
| Triangle, 120 ft base × 80 ft height | 4,800.00 sq ft | 4,800.00 | 0.1102 | 320.00 ft |
The worked example also produces 743.22 sq m and, at $25 per square foot, an estimated value of $200,000.00. Sanity-check the acres line by hand: 8,000 ÷ 43,560 = 0.1837 acres, a typical suburban parcel a little under a fifth of an acre. If a seller quotes you a price per acre instead, the cost per acre calculator works that direction of the same comparison.
Common lot sizes in acres
A quarter acre is 10,890 sq ft and a full acre is 43,560 sq ft; most US residential lots sit between about 5,000 and 15,000 sq ft. The bars below scale those landmarks against each other so the worked example has context.
| Unit | Equals | Where you meet it |
|---|---|---|
| 1 acre | 43,560 sq ft / 4,840 sq yd / about 4,046.86 sq m | Deeds, plats, rural listings |
| 1 sq m | 10.764 sq ft in this tool’s conversion | Metric listings and surveys |
| 1 sq yd | 9 sq ft exactly | Older US plats, landscaping quotes |
Which “lot” do you actually mean?
The word lot names at least four different quantities, and this page handles exactly one of them: the land parcel. The others live on their own pages, and using the wrong one gives you a confident, useless number.
- Land parcel (this page): area, acres, perimeter and a price-per-square-foot value estimate for a rectangle, square, circle or triangle.
- Trading lot size: the standardized unit count behind a forex or stock position (a standard forex lot is 100,000 units of the base currency). That is a position-sizing question about risk, answered by trading lot tools, not by measuring ground.
- Inventory or production lot: the order quantity that balances ordering and holding costs, the subject of the economic lot size calculator. Nothing to do with land.
- Parking lot: a paved area and its rent or stall count. A parking parcel’s ground area can be measured here, but stall layouts and parking rent are separate calculations.
Irregular lots: split, calculate, add
Most real parcels are not one clean shape, and this tool has no irregular mode. The standard workaround is to split the parcel into rectangles and triangles on the plat, run each piece through the matching shape here, and add the areas.
Two cautions make that work. First, keep every piece in the same unit before adding; the tool converts per run, so add the square-feet lines rather than the mixed-unit headlines. Second, gross lot area is not buildable area: setbacks, easements and rights-of-way shrink what you can build on without changing the parcel’s measured size. For a purchase, a boundary dispute or anything legal, treat this page as the fast check and the licensed survey as the answer.
What competing calculators miss
Most tools ranking for lot and acreage searches do one shape well and stop. The gaps below are what this page is built to close:
- AcreageCalculator.net and the acreage specialists: strong on rectangle acreage and acre FAQs, but rectangle-first: circles and triangles are prose formulas, not shapes you can select, and there is no perimeter or price estimate in the same run.
- Calc.awajis acreage calculator: clean length-by-width acreage with a handy common-lot-sizes table, but a single shape and no value estimate.
- ContractorCalcPro acreage calculator: honest surveyor framing and an irregular workaround, but the circle takes a diameter while most owners pace a radius, and irregular lots are handled by typing a finished square footage, which assumes you already did the geometry this page does for you.
- EverydayBudd plot area tool: good price-per-acre versus price-per-square-foot explanation, yet the plot tool itself is rectangular; wedge and round parcels are left to manual math.
- The gap this page fills: four selectable shapes, one consistent unit per run, area in four units plus perimeter in one result, an optional per-square-foot value estimate, and open disclosure of the two things rivals never mention: the single-unit rule and the isosceles assumption inside the triangle perimeter.
Frequently asked questions
It calculates the area of a land parcel shaped as a rectangle, square, circle or triangle. Every run returns the area in the unit you entered, plus square feet, square meters and acres, the perimeter in feet, and an estimated value when you add a price per square foot.
Multiply the length by the width. A lot 100 ft long and 80 ft wide is 100 times 80, which is 8,000 sq ft. Divide by 43,560 to get acres: 0.1837 acres.
One acre is exactly 43,560 square feet. It is also 4,840 square yards and about 4,046.86 square meters, roughly a square 208.71 ft on each side.
Yes. The unit select sits beside the first dimension and applies to the whole shape; the width and height fields have no unit of their own. Measure both dimensions in feet, both in meters, or both in yards before you calculate.
Split the parcel into rectangles and triangles on the plat or survey, run each piece through this calculator in the matching shape, and add the square-feet results. The tool has no irregular mode, and for a purchase or a boundary question a licensed surveyor’s figure is the one that counts.
Only for an isosceles triangle, one whose two slanted sides are equal. The perimeter formula rebuilds those sides from the base and the perpendicular height as if the apex sat over the middle of the base. The triangle area, half the base times the height, is exact for any triangle.
The tool multiplies the area in square feet by the price per square foot you enter, so 8,000 sq ft at $25 per square foot gives an estimated value of $200,000.00. Leave the price blank, at zero, or negative and no value line appears; the estimate is a comparison aid, not an appraisal.
No. In trading, a lot is a standardized number of units in a position, such as 100,000 units for a standard forex lot, and sizing it is a risk calculation. This page measures land parcels only; the shared word is the only thing the two tools have in common.
Add This Calculator to Your Website
Embed this calculator on your own site with the code below. Pick a size to preview it live, then copy the code.
Powered by Calculator Zilo
References
- National Institute of Standards and Technology. Guide for the Use of the International System of Units (SI), SP 811, Appendix B: Conversion Factors. Accessed October 22, 2026.
- U.S. Bureau of Land Management. Manual of Surveying Instructions (2009). Accessed October 22, 2026.
- Wolfram MathWorld. Circle. Accessed October 22, 2026.
- Wolfram MathWorld. Triangle Area. Accessed October 22, 2026.
- U.S. Census Bureau. Gazetteer Files: land area measurement documentation. Accessed October 22, 2026.